Fluval FX5

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Aquarium Advice Freak
Aug 1, 2007
I have had a fluval fx5 cannister for about a month now and the last two days it seems to be sending enormous amounts of micro bubbles into my aquarium. I thought I had it figured out yesterday however today it is just as bad if not worse. I can not for the life of me figure out how so much air is geting iside the filter. It automatically turns on for 2 mins, off for 2 and back on once a day to rid the filter of air inside it but it is constantly shooting air bubbles out every 30 seconds or so.

Anyone with a Fluval FX5 have any advice ?
I've been running an FX5 for almost 2 years and have never had that. One thing that comes to mind is there a bubbler anywhere near the intake tube?
thats what i kinda thought as well, the intake is on the left side of the tank and there is a protein skimmer in the middle - hte skimmer gives off some micro bubbles but nothing like is coming out of the fluval, I mean there are really coming out of there like crazy !!! Seems like no matter what something is always going wrong for me. I have been messing with it for the past few hours and can not for the life of me figure out where the excess air is coming from to create all these bubbles
I can't help you, but roka64 has a FX5 and may be able to help you when he gets online tommorow.

Only suggestion I have is to check all the fittings for air leaks, but it sounds as if you have already done so.
Have you noticed the water levels in the tank dropping at all.
When I first got the FX5 there was a hairline crack in the plastic cannister and it was letting air and and water out. Not a lot of water mind you but enough to notice. I also was getting air bubbles expelling from the outtake. If there is a crack you can find it by looking for white stress marks. Fluval and Petsandponds.com exchanged the cannister promptly for me and I had no further problems.
I noticed water coming out two days ago from the top, one of the fasteners was a little loose and I tightened it up however I am still geting the micro bubbles. I ordered mine off of Ebay - maybe I will have to contact Fluval if I am unable to stop the micro bubbles bc I am begining to think that the air is coming from the top and for some reason it will not tighten up as much as it is supposed too.
The fastners are supposed to be only hand tightened. You may have a hairline crack but find out you must empty out the cannister and apply pressure while looking at the rim to see if you can see a crack. Best to use a flashlight.
well I did not find any hair line cracks but now that I hooked it back up it doesnt seem to be shooting any bubbles out. I guess we will see what happens, thanks for you help ZAGZ
Sorry, I missed this whole conversation, I was Christmas shopping. Anne, sounds like you helped out. I haven't had any problems out of mine. Josh, let us know if you need anymore help! It does sound like you found the problem.
IMO doesn't matter if you use the FX5 for SW or FW the cannister is the same. :) Still shopping eh? I am done, LOL. :p
Zagz said:
IMO doesn't matter if you use the FX5 for SW or FW the cannister is the same. :) Still shopping eh? I am done, LOL. :p
Yep, I'm finished now! I do agree, the cannister should work the same for both SW and FW.
Well I just can not figure it out. I take it apart and put it back together and everything is fine for about 25 hours then the bubbles come back - something lets air in after it runs for a while

only thing I can think of is I wonder if it the fine filter pad causing the problem because I just started using those
Hmmm, take out the filter pad and see if it stops. The pad might just have some air in it.
Well the skimmer looks like it may be causing my air bubble problem. I didnt run the skimmer for two weeks and I had no bubbles, turned it back on and bubbles everywhere again. Is it possible that the the cannister can turn a small amount of bubbles from the skimmer into thousands of them? Im still considering contacting Fluval - I just cant tell what is causing my problem, I think it may be the skimmer but I just dont know - the skimmer has been off for ten mins but the bubbles keep flowing
Is the skimmer new, or has it been through it's "2 week" break in time?
the skimmer is six months old - everyonce in a while you will see a few bubbles come from it but nothing like what comes out of the fx5. I just cant figure out where they are coming from

Also have you ever noticed, exspecially when it the filter goes on and off, a large air bubble that comes out of the filter - enough to make a loud noise and create havoc at the top of the tank
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